Garlic is a common medicinal and edible plant that retains biological activities after harvest. It is prone to quality deterioration, including germination, browning, softening, and decay, during storage, leading to nutrient loss and serious economic losses. Preservation measures, such as low-temperature, controlled atmosphere, coating, and other methods, can effectively slow down the physiological activity of fresh garlic and reduce its respiratory intensity to maintain nutrients and achieve storage and preservation. In addition, transcriptomics and metabolomics methods allow a more accurate understanding of quality changes in garlic. This paper comprehensively summarizes the physiological changes and quality deterioration of fresh garlic during postharvest storage and systematically reviews advances in the application of postharvest quality preservation technology and analytical methods in fresh garlic. These findings can serve as a theoretical reference for the development of high-quality products and for the improvement of industrial quality and efficiency of fresh garlic in the future.